Alarm device for armature-shafts.



No. 665,3l9. Patented Jan. I, I90l. F. W. GARRETT.

ALARM DEVICE FOR ABMATURE SHAFTS.

(Application filed Sept. 16, 1899.) (No Model.)

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PATENT (Enrica.

FRANK W. GARRETT, OF JOHNSTOVVN, PENNSYLVANIA, ASSIGNOR TO THE LORAIN STEEL COMPANY, OF PENNSYLVANIA.

ALARM DEVICE' FOR ARMATURE-SHAFTS.

SPECIFICATION forming part of Letters Patent No. 665,319, dated January 1, 190i.

Application filed September 16, 1899. Serial No. 730,695. (No model.)

T0 at whom it may concern:

, Be it known that I, FRANK W. GARRETT, of Johnstown, in the county of Cambria and State of Pennsylvania, have invented a new and useful Improvement in Alarm Devices for Armature-Shafts, of which the following is a full, clear, and exact description, refer ence being had to the accompanying drawings, which form a part of this specification.

My invention has relation to an automatic alarm more especially designed for use in connection with electric motors for the purpose of indicating displacement of the armatureshaft due to wear of bearings, and thereby enabling the motor to be stopped before the armature has become injured by contact with the pole-pieces of the motor. Armatures are frequently seriously injured or completely wrecked in this manner, the undue wear of the bearings being overlooked from neglect or difficulty of inspection, and it is very desirable to provide means which will automatically indicate when the wear has reached the danger-point.

The present invention is designed to provide means of this character capable of being used with a single motor or with any number of motors, which can be readily applied to any motor without changing the motor construction and with very little machine-work, which involves the use of but few mechanical parts, and which does not require an independent source of current for its operation, its current being derived from the motor-circuit.

The invention also provides means for indicating, when the device is used. in connection with two or more motors, at which motor the trouble exists.

It also provides means whereby the alarmcircuit may be tested any time to insure its proper working condition; also, means for indicating the presence of water in the motor frame or casing.

The invention is more particularly designed for use in connection with the driving-motors of electrically-propelled vehicles wherein the iron-clad motor armature-bodies are connected to ground through the armature-shaft, motor-frame, and vehicle axle and wheels in the usual manner; but it may be applied to any electric motor in which an electrical connection can be made between the armature-body and the return side of the circuit.

I accomplish the objects of my invention by the mechanism now to be described and hereinafter pointed out in the claims, reference being had to the accompanying drawings, in which- Figure 1 is a sectional view of a portion of an electric motor, showing my invention applied thereto, the alarm-circuit being indicated diagrammatically. Fig. 2 is a detail view of the contact device. Fig. 3 is a dia gram showing the application to two motors. Fig. 4 is a similar view showing different means for indicating at which motor the trouble exists, and Fig. 5 is a diagram showing a circuit arrangement suitable for use upon a double-end electric car having two motors.

In the drawings the letter A designates a motor frame or casing, B its pole-pieces, and C the armature.

The motors indicated in the drawings are of the usual type of railway-motors in which the metallic armature body or core is electrically connected to ground or to the returnrail through the armatu re-shaf t, motor-frame, and running-gear of the car.

D designates a lug or bracket which is sccured within the motor frame or casing between the pole-pieces B by means of a bolt 61, tapped into the motor frame or casing. Supported by, but insulated from, this lug or bracket is a metallic piece E, having a depending arm E, whose lower end extends to within a short distance of the motor frame or casing, and also a slotted seat for a contact piece or brush E. This brush is preferably of brass, phosphor-bronze, or some other conductive metal possessing sufficient flexibility to bend under contact with the armature. The upper edge of this brush projects a slight distance beyond the face of the pole-pieces, the extent of such projection being regulated by means of thin shims e, placed under the lug or bracket D.

E designates a wire conductor which leads from the piece E out through the motor frame or casing and is connected to one side of the main circuit at T. Although not so shown,

this wire F may be brought out through the frame or casing at the same point as the leads for the field-coils,-thus obviating the necessity for making a special opening therefor. Included in the conductor F is the alarm or indicator, which preferably consists of a number of incandescent electric lamps L.

The operation will be readily understood. The moment that the armature-shaft becomes displaced to such an extent as to cause the armature to contact with the brush a circuit is at once completed from the point T, through the conductor F, the metallic piece E, brush E and armature, to ground, and the lamps L are lighted and remain lighted until the motor is stopped or the circuit therethrough is broken. tric hell or other signal may, if desired, be used instead of or in conjunction with the said lamps. It will also be seen that an accumulation of water within the motor frame or casing to a sufficient depth to touch the arm E will complete a circuit through the lamps to ground, and thus indicate its presence.

in the diagram Fig. 3 the two electric motors marked No. 1 and No. 2 are indicated. F F are the conductors from the contact devices or brushes E of said motors, as in Fig. 1, each of these conductors being connected to line at T through four lamps Land also through an additional lamp, which may be distinguished from the others by being numbered, as indicated, or by being difierently colored or in any other suitable manner. The four lamps L will light upon displacement of either of the two armatureshafts; but lamp No. 1 will only light by a displacement of the shaft of motor No. 1 (or water in the frame) and lamp No. 2 by a displacement of the shaft of motor U0. 2.

For the purpose of testing the alarm-circuits at any time I may provide the connections P and switches P, the latter having one terminal connected to I and the other to ground. If the alarm-circuit is in proper condition, the closing of the switches P will complete the circuits through the lamps and light them, as will be readily seen.

In the modification shown in Fig. 4 instead of the lamps No. 1 and No. 2 I place a normally-closed switch 0 or 0 in each of the conductors F F. In this arrangement the lamps will light when trouble occurs at either motor. it now switch 0 be opened and the lamps go out, it shows the trouble to be in motor No. 1. it, however, the trouble is in motor No. 2, the opening of the switch 0 will not affect the lamps.

Fig. 5 shows the circuit arrangement for two motors on a double-end electric car. This arrangement is the same as in Fig. 3, except distingdishing-lamps are placed at both ends of the car, corresponding lamps being connected in series.

1t is obvious that many different kinds and arrangement of signals may be used in lieu of those herein described; also, that various It is obvious that an elecchanges may be made in the details shown and described without departing from the spirit and scope of my invention.

An important feature of the invention is that it is not necessary to cut into or in any way disturb the pole-pieces of the motors and that no change isrequired in the motorframe beyond the simple provision of a hole for the bolt which secures the bracket D.

Having thus described my invention, what I claim, and desire to protect by Letters Patcut, is

1. The combination with the frame or casing of an electric motor, its pole-pieces, and

the armature having its body electrically connected to one side of the line-circuit, of a device located within the said frame or casing between the pole-pieces and in position to be engaged by the armature upon displacement of its shaft, and an electrical connection between said device and the other side of the line-circuit, together with a signal included in said connection, substantially as described.

2. The combination with the frame and armature of an electric motor said armature having its body electrically connected to one side of the line-circuit, of a flexible contact device arranged within said frame or casing between its pole-pieces for engagement with the armature upon displacement of the armature-shaft, and an electrical connection between said device and the other side of the line-circuit, together with a signal in said connection, substantially as described.

3. The combination with the frame and armature of an electric motor said armature having its bodyelectrically connected to one side of the line-circuit, of a lug or bracket secured in the motor-casing, a flexible contact device carried by said lug or bracket and projecting into the space between the armature and pole-pieces, an electrical connection between said device and the other side of the line-circuit and a signal included in said connection, substantially as described.

1-. The combination with the frame, polepieces, and armature of an electric motor said armature having its body electrically connected to one side of the line-circuit, of a contact device within said frame and projecting into the space between the pole-pieces and armature, and also having an arm extending to within a short distance of the motor-casing, an electrical connection between said device and the other side of the line-circuit, and a signal device or devices included in said connection, substantially as described.

5. The combination with a plurality of electric motors a device in each motor for contact with the armature upon displacement of its shaft, and a connection between each of said devices and one side of the motor supply-circuit, a number of signals interposed in said connections, some of said signals being common to all the said connections, and

others included only in the individual connections, and means for distinguishing the individual signals from each other.

6. The combination of two or more electric motors, a contact device in each motor normally connected to the supply side of the motor-circuit a distinguishable signal in such connection, means for automatically connecting said device to the opposite side of thei motor-circuit upon the occurrence of certain abnormal conditions in its motor and means for arbitrarily effecting such connection for test purposes,said last-named means comprising an electrical connection between said device and ground and a normally open switch in said connection.

In testimony whereof I have aifixed my signature in presence of two witnesses.

FRANK W. GARRETT. Witnesses:

MYRTLE E. SHARPE, H. W. SMITH. 

